Why are BMIs useful ?

Why are BMIs useful?

The BMI measures an easy and inexpensive screening instrument that can be used to detect concerns with weight in adults as well as children. The BMI estimation can be important to determine who needs additional testing to determine risk factors for heart disease. People who are at risk require additional assessment. Tests can include measurements of the thickness of the folds of the skin as well as diet, physical activity level, family history and other appropriate health screenings.

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Risks due to extreme BMIs

BMIBeing or overweight (with an BMI that is 25 or higher) or being underweight (with a BMI less than 18.5) can affect your health.

Overweight

People who are overweight or obese are at a higher chance of developing diseases than those who are in those who are in the normal weight range. The risk of developing diseases increases when you increase your BMI. Individuals who are overweight (BMI 25-29.9) could also be classified as pre-obese and at greater risk of diseases. In Category 1 obesity (BMI 30-34.9) the risk of developing a mild risk of developing the disease. It increases to severe and very severe risk at obesity stages 2 (BMI 35-39.9) as well as 3 (BMI greater than 40) respectively.

It is important to realize that BMI does not determine risk on its own. Other factors such as what one eats, the amount they exercise, and the presence of any medical history within their families can also affect the risk of a person developing disease. As a group the obese and overweight have a higher risk of various diseases.

They are at risk of a high probability of

  • Type 2 Diabetes;
  • Gall bladder disease
  • Hypertension;
  • Dyslipidaemia;
  • Insulin Resistance;
  • Atherosclerosis;
  • Sleep apnoea;
  • Breathlessness
  • Asthma;
  • Depression and social isolation.
  • The fatigue and sleepiness of the day.

They have a moderately increased likelihood of:

  • Cardiovascular diseases (i.e. stroke, heart attack);
  • Gout /hyperuricaemia;
  • Osteoarthritis;
  • Respiratory diseases;
  • Hernia;
  • Psychological problems.

They have a slightly higher chance of:

  • Certain types of cancer (breast colon, endometrial and breast cancers);
  • Reproductive abnormalities;
  • Infertility impairment;
  • Polycystic ovarian Syndrome;
  • Skin conditions;
  • Cataract;
  • Varicose veins;
  • Conditions of the Musculoskeletal system;
  • Bad back;
  • Incontinence due to stress
  • Oedema/cellulitis.

Underweight

People who are overweight may be undernourished. They also have an increased chance of developing health issues, including:

  • Inflammatory dysfunction that is compromised and a higher susceptibility to infections;
  • Anaemia;
  • Osteoporosis;
  • Menstrual irregularities;
  • Unhealthy fertility.


What are the limits of the BMI?

BMILimitations that are associated with the BMI are:

  • BMI can vary based on age gender and race. So, a person's BMI can only be compared to that with the same sex race and age.
  • BMI doesn't distinguish between muscle and fat and will therefore underestimate in certain cases and overestimate in others (e.g. An athlete could have an elevated BMI because they have a larger amount of muscle rather than fat).
  • The elderly or disabled have less muscle mass , and therefore will have a lower BMI. It does not mean that their weight is not normal or even underweight.
  • Pregnant women also will be more obese BMI due to increased weight that is associated with pregnancy, however, not necessarily due to increased fat. BMI will overestimate body fat in this situation. Pre-pregnancy BMI and weight growth during pregnancy must be used to evaluate the weight of a woman and the necessity of exercise and nutritional interventions.
  • BMI doesn't distinguish between the body's fat distribution. The fat that is located around the waist ("apple" physique) is more harmful than hips ("pear" body shape) However, this is not reflected as a result of BMI.

See your healthcare provider for other physical measures that may need to be used along with BMI for assessing health risk caused by overweight.


Other ways to measure overweight


Table 2 Other indicators of obesity

Measure Description
Waist circumference The circumference of your waist (WC) is an effective measure of abdominal fat, and can be used to determine health risk. It's measured by placing an unstratified tape measurement around the narrowest level of your waist. This is done over light or no clothing.For men:>94 (37 inches) - increased risk> 102 cm (37 inch) greater risk of being ill than 102 cm (40 inch) - substantially increased riskFor women:>80 cm ( 31 inches) - increased risk> the 88-cm (35 inch) A significantly higher risk is also dependent on your ethnicity and the risk of health is greater with a lower waist circumference in certain ethnic groups including Aboriginal, Pacific Islander, South Asian, Chinese and Japanese populations.
Hip circumference The hip circumference (HC) is determined by placing a piece of tape over the widest area of your hip , layered over only a small amount of clothes. HC isn't useful on its own; usually it is used as an equivalent ratio to WC as mentioned previously mentioned.
Waist-hip ratio Waist to Hip ratio (WHR) is the ratio of your waist circumference to hip circumference. For females , the typical WHR is approximately 0.80 and for males it's 0.95.
Waist-height ratio Waist-to-height ratio is the proportion of the circumference of your waist to your height.

More details

For more information on nutrition, including information on types and composition of food along with nutrition and individuals as well as conditions that relate to nutrition and diets, as well as recipes and diets and some useful videos and other tools look up Nutrition.
For more information on overweight, social health, as well as ways to lose weight, and a variety of useful tools, check out the article Weight Loss.

References

  1. National Health and Medical Research Council. Clinical Management Guidelines for the management of obesity and overweight adults, adolescents and children in Australia. 2013. [cited 14 April 2014]. Available from: [URL Link[URL Link]
  2. Centre for Disease Control and Prevention. About BMI for Adults. 2011. [cited as 14 April 2014] Available at: URL Link]
  3. Keys A, Findanza F, KarvonenMJ, et al. Indices of weight relative and obesity. J Chron Dis. 1972; 25: 329-43. [Abstract]
  4. Goh LGH, Dhaliwal SS, Welborn TA, et al. Anthropometric tests of general and central obesity and prediction of cardiovascular disease risk in women: a cross sectional study. BMJ Open. 2014: 4; e004138 doi:10.1136/bmjopen-2013-004138 [Full Text]
  5. Snijder MB, van Dam RM, Visser M, Seidell JC. What elements of body fat are especially dangerous and how can we determine their severity? Int. J. Epidemiol. 2006;35(1):83-92. [Full Text]
  6. Gill T, Chittleborough C, Taylor A, Ruffin R, Wilson D. Body mass index as well as waist hip ratio along with waist circumference Which indicate the degree of overweight. Int J Public Health. 2003;48(3):191-200. [Full Text]
  7. Pouliot Ma, Despers J Lemieux S, Moorjan S. Waist circumference and abdominal sagital diameter: best basic anthropometric measures of the abdominal visceral adipose tissues accumulation and the associated cardiovascular risk for men and women. Am J Cardiol. 1994; 73(7): 460-8. [Abstract]
  8. Schneider J, Glaesmer H, etal. Accuracy of anthropometric indicators of weight to predict cardiovascular risk. J Clin Endocrinol. 2007; 92(2): 589-594. 789-594. Full text]
  9. Kunesova M, Hainer V, Hergetova H, Zak A. Simple anthropometric measurements - relation to visceral adipose tissues and the risk factors for atherogenesis. SB Lek. 1995; 96(3): 257-67. [Abstract]
  10. Seidell JC, Perusse L, Despres J-P, Bouchard C. Waist and hip circumferences exhibit independent and opposing effects on cardiovascular risk factors. The Quebec Family Study. Am J Clin Nutr 2001; 74(3): 315-321. [ Full Text]
  11. Mukuddem-Petersen J, Snijder MB, et al. Sagittal abdominal size: no advantage compared with other anthropometric measures to be a marker of components of metabolic syndrome among the elderly in the Hoorn Study. Am J Clin Nutr. 2006; 84(5): 995-1002. [Abstract]
  12. Lean Mo. Waist Circumference as a measure for an indication of the need for weight control. BMJ 1995;311:158-161. [Full Text]
  13. Esmailzadeh A Mirmiran P, Azizi F. Waist-hip proportion is a better screening measure for cardiovascular risk factors as compared to other anthropometric markers in Tehranian adult males. Int J Obesity 2004; 28: 1325-1332. [Ab`stract]
  14. Australian Government Department of Health. About Overweight and Obesity. 2009. [cited 14 April 2014] Available from:[ URL Link]
  15. NHS Choices. Underweight Adults. 2012. [cited 14 April 2014]. Available from:

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